Patent GB-340308-A (GB)
Title: Improvements in or relating to telephone or like systems
IPC: H04M3/22
Filed: 1929-09-25
Abstract: 340,308. Automatic exchange systems. AUTOMATIC TELEPHONE MANUFACTURING CO., Ltd., and CASWELL, A. E., Ingleside, both in Milton Road, Edge Lane, Liverpool. Sept. 25, 1929, No. 29100. [Class 40 (iv).] In automatic routiner equipment, the distributing apparatus by means of which each of a large number of similar pieces of apparatus to be tested is seized in turn is formed as a unit separate from the apparatus by which the actual tests are applied so that substantially standard distributing apparatus may be used for routiners of varying types. Figs. 1 .. 4 show such distributing apparatus associated with the test apparatus proper over leads 37 .. 22. The pieces of apparatus to be tested are connected to the banks of direct access switches ACS, twenty to each switch, these switches ACS being associated in groups of twenty-four with secondary distributors SAD which are similarly associated with a primary distributor PAD. The leads from the test apparatus pass over wipers of the direct access switches ACS only. The stepping magnets of all the switches PAD, SAD, ACS are operated from a common impulse mechanism under the control of switches PPD, SPD which distribute the impulses to the magnets in proper sequence. The switches ACS are provided with normal positions and the arrangement is such that each of these switches is unable to move from normal until the preceding one has returned to normal. The test-applying wipers of each switch ACS are connected to the normal contacts of the preceding switch so that only one piece of apparatus can be connected to the routiner at one time. Normal operation of distributing apparatus. The start key STK energizes relay ST, and relay S operates over normal contacts of switch PPD starting up the pulse machine over lead 10 whereby pulses are supplied over lead 11 to relay IP. Magnet PPM operating over bank 1a moves switch PPD to position 2. The first pulse operates relay PA which locks in series with relay PB whereby further pulses are repeated to relay A and thence to magnet PPM. In position 3 of PPD wiper 3a connects up lead 12 so that at the next pulse relay IP repeats the pulse to magnet SPM of switch SPD. In positions 4 of PPD and 2 of SPD a pulse is transmitted over lead 14 and wiper 4b to magnet PAM of switch PAD which moves to position 2 to connect up magnet SAM of the first secondary distributor SAD. In position 5 of PPD a pulse is transmitted to magnet SPM which moves to position 3, and in position 6 of PPD a pulse is transmitted over wipers 3a, 4b, 5c to magnet SAM which moves to position 2 to connect up the first direct-access switch ACS. In position 7 of PPD a further pulse is sent to magnet SPM and in position 8 a pulse is transmitted over wipers 3a, 4b, 4c, 4d to magnet ACM which connects up the first piece of apparatus to be tested. A circuit is completed over wiper 1e for lamp 19 in series with relay NA which operates to cut off the pulses and to release relay S thus restoring switch PPD to normal. Relay NA also connects ground to the " test start " lead 21. When the first piece of apparatus has been fully tested, ground extended over the " test finished " lead 22 operates relay TF, which releases relay NA so that pulsing recommences. In position 2 of PPD an impulse is transmitted to magnet ACM to select the next piece of apparatus, and in position 3 relay H operates and extends the ground from lead 22 over the " homing " lead 24. Relay H also releases relay TF permitting relay NA to operate again to stop the pulsing. When the test apparatus is completely restored the removal of ground from lead 22 releases relay H permitting the next test to start. When all the pieces of apparatus associated with switch ACS have been tested wiper 1e connects up relay AR which operates relay AS. Switch SPD. steps automatically over its bank 2b to position 7 (equivalent to position 3) so that a pulse will be transmitted over wiper 4b to switch SAD. Switch ACS automatically returns to normal in which position the release of relays AR, AS permits the next test to start. In a similar manner, when switch SAD reaches the end of its bank relay DS operates and moves switch SPD to its second position to direct an impulse to magnet PAM. When all the pieces of apparatus have been tested, relay AT operates over a wiper of the last direct-access switch and lead 26 and energizes relays AS, RF, lighting lamp RFL and operating relay AL which connects up alarm bell ALB, rack alarm lamp RAL, and a main alarm over lead 28. The restoration of key STK completes restoring circuits for switches SPD, PAD, SAD. Back contacts of relays AH, AJ controlled by relay ST ensure the return to normal of the direct-access switches ACS in the event of the key STK being restored during testing. Unequipped positions in the switches ACS are passed over by wiring the corresponding contacts in bank 1e to lead 29 causing the operation of relay PU which holds relay TF operated over wiper 3b so that a further impulse is transmitted over wiper 4b. Vacant positions in switches PAD, SAD are similarly passed over owing to ground connections in the banks 3c, 3d. The banks 3c, 3d also serve in conjunction with keys GSK to effect the selection of any particular group of pieces of apparatus to be tested. Reset and step-on keys. Key RSK controls relay RE which energizes relay RH, opens the " test hold " circuit over lead 30, and opens the pulse circuit to wiper 4b. The test equipment is then returned to normal after which the test is repeated on the same piece of apparatus. Step-on key SOK and relay SO operate in a similar manner, but without opening the lead to wiper 4b so that a test will be commenced on the next piece of apparatus. Continuous routine of particular piece of apparatus. Key CRK operates relay CR in addition to the starting relay ST. A particular piece of apparatus is selected by transmitting impulses by means of key ASK over wiper 4b in positions 2, 3, 4 respectively, to switches PAD, SAD, ACS, switch SPD being automatically advanced to position 2 by relay CR and then moved at will to positions 3 and 4 by operating key DSK to the right and left respectively. Lamp banks L1, L2, 19 indicate the positions of switches PAD, SAD, ACS. Relay CR also grounds the " continuous routine " lead 31, and connects " test finished " lead 22 to " homing " lead 24. The continuous routine test on the selected piece of apparatus is started by operating key STK. By means of the step-on key SO the continuous routine test can be transferred to the next piece of apparatus. Faults. If a lamp 19 becomes short-circuited, relay SL operates to light lamp SCL and operate alarm relay AL which controls local and main alarms as described above. If a direct-access switch ACS fails to return to normal, relays AR, AS remain operated for an extended period. Relay AS energizes relay ZA over grounded lead 32, starting up the time-pulse machine over lead 33. After a predetermined period a pulse over lead 34 operates relay ZB which short-circuits the right-hand winding of ZA to light lamp ACF, and grounds main-alarm lead 35. If any of switches PPD, SPD, PAD, SAD, stick, the continued operation of relay RB in series with all the stepping magnets similarly controls the time-alarm circuit and lights lamp DTF, whilst if the test switch (not shown) sticks relay RA in a similar manner lights lamp TSF.